The present invention relates to IC test equipment, and more particularly to its IC loading-unloading arrangement which feeds IC elements to a testing station, sorts them according to their test results and houses them in an unloading station.
In this kind of IC test equipment, an IC element supplied to a testing station is guided sliding on a rail and once stopped by an auxiliary stopper immediately before a test position, and then the auxiliary stopper is released to let the IC element slightly slide on the rail toward the test position, where it is stopped by a main stopper. In the case where no such an auxiliary stopper is provided and hence the IC element is stopped directly by the main stopper, if the IC element slides down fast, it often strikes so hard against the main stopper that terminal pins of the IC element are bent to make it defective and its test cannot be effected at the correct position. Sometimes the testing station is designed to let the IC element down by its own weight substantially vertically to the test position, and in such an instance, its descending speed is appreciably high.
Conventionally, the auxiliary stopper is formed by a resilient wire, which is disposed opposite but aslant to one side of the rail and the lower end of which is held in resilient contact with the rail so that the terminal pins of the IC element sliding down the rail come into contact with the auxiliary stopper whereby the element is braked to stop. Since IC elements vary in weight five to six times or more according to their types, their kinetic energy during movement considerably scatters, and their thicknesses and widths also substantially differ. Therefore, the position where the IC elements are stopped by the auxiliary stopper appreciably varies, and even if the auxiliary stopper is employed, their terminal pins are often bent when they are stopped by the main stopper. Moreover, since the auxiliary stopper is held in resilient contact with the side surface of the rail, the contact surface of the rail with the auxiliary stopper is sometimes worn or scratched by repeated engagement and disengagement between the auxiliary stopper and IC elements, introducing the possibility that terminal pins of the IC element are caught by such worn or scratched surface of the rail and the element cannot be moved to the main stopper. Further, when the IC element is slid down vertically, a guide member is disposed opposite the sliding surface of the rail so as to prevent the IC element from running off the rail. The guide member is made movable so that the testing station can be inspected, but when the guide member is moved back away from the rail, the IC element held by the auxiliary stopper on the rail falls off because only the terminal pins of the element are urged against one side of the rail.
Sometimes IC elements are tested at a predetermined elevated temperature. In this instance, in order to heat the IC elements to the predetermined temperature in the testing station, or to hold preheated IC elements at that temperature, a heater is provided in the testing station. A guide member is positioned opposite the IC element sliding surface of the rail for preventing it from running off the rail, and the heater is incorporated in the guide member or the rail, or provided between them. In the prior art, a recess or groove is cut in the guide member or rail to extend in its lengthwise direction and a bar-shaped heater is buried in the groove. The bar-shaped heater is coated with silicone grease so as to facilitate good conduction of heat from the heater to the guide member or rail.
However, since the bar-shaped heater is appreciably low in temperature at both ends thereof and since the heater is buried in a long and thin groove, temperature in the contact surface of the guide member or rail with the IC element is not uniformly distributed, and consequently, the IC element cannot satisfactorily be heated. Besides, the use of the silicone grease involves an additional step therefor in the manufacture of the equipment.
With a view to speeding up the test, there has been proposed equipment which has two testing passages in the testing station for simultaneously testing IC elements in both passages. According to this prior art equipment, the tested IC elements are transferred onto discharge rails respectively corresponding to the passages, and in a sorting station, the IC elements are transferred from one of the discharge rails to one sorting rail, which is moved in the direction of arrangement of a plurality of receiving rails, and the IC elements on the sorting rail are each delivered onto a predetermined one of the receiving rails according to its test results, that is, depending upon whether it is non-defective or defective, or according to its quality. Thereafter, the IC elements on the other discharge rail are similarly transferred to the sorting rail and then selectively delivered to the receiving rails.
With such a sorting station, a relatively long time is needed for transferring the IC elements to the unloading station. This poses a problem in the processing speed in the sorting station especially when the time for testing one IC element is short, or when more testing passages are provided.